COLONIZATION IN THE RECTUM AND UTERINE CERVIX WITH GROUP-B STREPTOCOCCI MAY INDUCE SPECIFIC ANTIBODY-RESPONSES IN CERVICAL SECRETIONS OF PREGNANT-WOMEN

We have studied the relationships between genital or rectal carriage o f group B streptococci (GBS) with the levels of systemic and mucosal a ntibodies to GBS in 200 women at about week 17 of pregnancy. Secretion s from the uterine cervix were collected with absorbent cylindrical wi cks for quantification of antibody levels with whole cell enzyme-linke d immunosorbent assay. GBS were cultured from the cervix (with or with out concomitant rectal colonization) of 13.5%, from the rectum (with o r without concomitant cervical colonization) of 12%, and from both cul ture sites of 8.5% of the women. Serotypes Ia, II, and III were predom inant. Compared with culture-negative women, the group of women coloni zed rectally had markedly elevated levels of both immunoglobulin A (Ig A) and IgG antibodies to GBS in cervical secretions and also had a mod erate but significant elevation of IgA antibodies in sera. Women colon ized only in the cervix had increases of specific IgA and IgG antibodi es in cervical secretions, but their serum antibody levels were not el evated. In cervical secretions, the increase in antibody levels in the groups of colonized women was most pronounced for the IgG isotype, in dicating a mucosal immune response involving IgG as well as IgA. A clo se correlation was found among the levels of antibodies to each of the three GBS serotypes tested, Evidence for such cross-reacting antibodi es to different serotypes of GBS, as well as to group A streptococci, was also obtained from absorption experiments. Altogether, our results show that undiluted secretions for antibody determination can be easi ly collected from the uterine cervix with absorbent wicks and demonstr ate that colonization of GBS in the rectum and the uterine cervix may induce a systemic as well as a pronounced local immune response in the female genital tract. The findings may have implications for the deve lopment of a mucosal vaccine against GBS disease.